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School officials say the package was turned over to authorities within hours of delivery

A woman shot in the head survives, thanks in part to a brain abnormality

Authorities on Monday discovered a package in a mailroom at the University of Colorado - Anschutz Medical Campus apparently sent by the alleged gunman responsible for the theater shooting that left 12 people dead and scores injured, a law enforcement official briefed on the investigation said Wednesday.

It was sent to the school's campus in Aurora, where the suspect, James Holmes, had recently dropped out of a Ph.D. program in neuroscience.

CBS News reported that the package was addressed to a psychologist at the university.

"Sources say the letter was from a pent-up Holmes to one of his professors," the news organization reported. "In it, he talked about shooting people and even included crude drawings of a gunman and his victims."

School officials said in a statement that a package discovered at the Facilities Services building on Monday had been delivered to the campus by the U.S. Postal Service that same day and was turned over to authorities within hours of delivery.

"This package prompted the building's evacuation at 12:26 p.m. and employees were allowed to return by 3:06 p.m.," the statement said.

Colorado movie theater massacre 51 photos

Colorado movie theater massacre51 photos

Colorado movie theater shooting – The public gets its first glimpse of James Holmes, 24, the suspect in the Colorado theater shooting during his initial court appearance Monday, July 23. With his hair dyed reddish-orange, Holmes, here with public defender Tamara Brady, showed little emotion. He is accused of opening fire in a movie theater Friday, July 20, in Aurora, Colorado, killing 12 people and wounding 58 others. More photos: Mourning the victims of the Colorado theater massacre

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Colorado movie theater shooting – Police release the official photo from Holmes' booking after the shooting.

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Colorado movie theater shooting – Holmes often had a blank stare during his court appearance Monday, appearing to be in a daze.

Colorado movie theater shooting – Flags fly at half-staff Monday at the Arapahoe County Courthouse in Centennial, Colorado, where the movie theater shooting suspect had his first court appearance. The prosecutor held a press conference outside the courthouse.

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Colorado movie theater shooting – Arapahoe County District Attorney Carol Chambers talks to reporters Monday before heading into the courthouse. Chambers said the decision on whether to pursue the death penalty is a long process that involves input from victims and their families.

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Colorado movie theater shooting – Family members of the victims arrive at the courthouse Monday for the suspect's first court appearance.

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Colorado movie theater shooting – The Century Aurora 16 multiplex in Aurora becomes a place of horror after a gunman opened fire Friday in a crowded theater. At least 17 people remained hospitalized late Sunday, July 22, in the shooting rampage that shocked the nation.

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Colorado movie theater shooting – Holmes is accused of opening fire during a midnight screening of the new Batman movie, "The Dark Knight Rises." Holmes purchased four weapons and more than 6,000 rounds of ammunition in recent months, police say.

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Colorado movie theater shooting – Police investigate outside the Century 16 multiplex Saturday, July 21, a day after the mass shooting. Authorities have been tight-lipped about a possible motive in the case.

Colorado movie theater shooting – People mourn the victims during a vigil behind the theater where a gunman opened fire on moviegoers in Aurora.

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Colorado movie theater shooting – A woman grieves during a vigil for victims behind the theater.

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Colorado movie theater shooting – A distraught woman receives counseling from Pastor Quincy Shannon, left, in front of Gateway High School in Aurora, where the families of the missing met following the shooting.

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Colorado movie theater shooting – Lin Gan of Aurora holds back tears as she speaks to reporters about her experience in the Century 16 theater Friday.

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Colorado movie theater shooting – People embrace before a vigil for victims behind the theater where a gunman opened fire on moviegoers.

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Colorado movie theater shooting – Investigators work on evidence near the apartment of James Holmes on Friday.

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Colorado movie theater shooting – Members of the Aurora Police Department SWAT unit walk near the apartment of James Holmes. Police have Holmes, 24, of North Aurora, in custody.

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Colorado movie theater shooting – Television news crews gather in front of the home of Robert and Arlene Holmes, parents of 24-year-old mass shooting suspect James Holmes, in San Diego, California, on Friday.

Colorado movie theater shooting – An NYPD officer keeps watch inside an AMC move theater where the film "The Dark Knight Rises" is playing in Times Square on Friday. NYPD is maintaining security around city movie theaters following the deadly rampage in Aurora, Colorado.

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Colorado movie theater shooting – Adariah Legarreta, 4, is comforted by her grandmother Rita Abeyta near the Century 16 Theater in Aurora.

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Colorado movie theater shooting – A cyclist and pedestrians pass a theater showing the latest Batman movie in Hollywood, California, on Friday. Warner Brothers said it was "deeply saddened" by Friday's massacre at a Colorado screening of "The Dark Knight Rises."

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Colorado movie theater shooting – Obama supporters observe a moment of silence for the victims at a campaign event at Harborside Event Center in Fort Myers, Florida, on Friday.

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Colorado movie theater shooting – Jessica Ghawi, an aspiring sportscaster, was one of the victims.

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Colorado movie theater shooting – A woman waits for news outside Gateway High School, a few blocks from the scene of the shooting at the Century Aurora 16.

Colorado movie theater shooting – Investigators were a common sight at the theater Friday.

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Colorado movie theater shooting – Authorities gather at the shooting suspect's apartment building in Aurora. Police broke a second-floor window to look for explosives that the suspect claimed were in the apartment.

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Colorado movie theater shooting – Screaming, panicked moviegoers scrambled to escape from the black-clad gunman, who wore a gas mask and randomly shot as he walked up the theater's steps, witnesses said.

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Colorado movie theater shooting – University of Colorado Hospital spokeswoman Jacque Montgomery said that all of the wounded had injuries from gunshot wounds, ranging from minor to critical.

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School administrators said that Holmes had taken his preliminary examinations at the school on June 7.

A source familiar with Holmes' academic status said the 24-year-old suspect did "poorly" on the oral exam.

Three days later, Holmes initiated his withdrawal from the program.

"It's very unusual, very unusual for a student to withdraw from our program," Dean Barry Shur told reporters on Monday.

Holmes did not divulge his reason for leaving the elite program. "That area of the form was left blank," Shur said.

Meanwhile, a composite image began to emerge of Holmes as a child; his classmates at Castroville Elementary School in northern California, where he grew up, referred to him as "Jimmy."

But that picture revealed no immediate answers as to possible motive. "He was top of the class," Adam Martinez said. "He was ahead of every student academically."

Martinez added, "He got along well with everybody."

Holmes' fifth-grade teacher there said the matter has led to introspection. "It's really disturbing to be so close to something like that -- bothers you to your essence," Paul Karrer said. "And particularly, as a teacher, you're thinking, this is one of my kids. And then you also think: Could I have done anything? Or did I see anything? Did I miss anything? You know, could I have done anything to have prevented this? Did I do anything to cause this? The answer is no, but that's what you think and that's how you feel."

As of Wednesday evening, five area hospitals were still caring for 17 patients, six of whom were in critical condition.

Several of the hospitals said they would pay for the medical care of uninsured victims out of charity funds.

Holmes made his first court appearance Monday.

The man who identified himself to police as "the Joker" will continue to be held without bond. He is to be formally charged July 30.

Meanwhile, families grappling with Friday's carnage were beginning to bury the dead.

On Wednesday, a memorial service was to take place for 51-year-old Gordon Cowden, who took his two teenage children to see the midnight premiere of the Batman movie "The Dark Knight Rises." Cowden's children survived the shooting inside the Aurora theater.

Nine miles away, visitation was to take place for Micayla Medek, a 23-year-old woman who had been working toward her college degree.

Those who were wounded still face the specter of permanent injury and long recovery periods.

In Aurora, actor Christian Bale, star of "The Dark Knight Rises," visited a memorial for the dead and met Tuesday with survivors, CNN affiliate KDVR reported.

One of the victims, Carey Rottman, posted a picture of Bale visiting him in his hospital room on Facebook.

"Wow! Thank you so much for the visit Christian! What a great guy! Still in shock!" Rottman wrote, KDVR reported.

Petra Anderson suffered four shotgun wounds, including one to her head. But thanks, in part, to a brain abnormality, she survived, her pastor said.

"The doctor explains that Petra's brain has had from birth a small 'defect' in it," Brad Strait of Cherry Creek Presbyterian Church in Englewood, Colorado, wrote on his blog. "It is a tiny channel of fluid running through her skull, like a tiny vein through marble, or a small hole in an oak board, winding from front to rear."

"Like a marble through a small tube, the defect channels the bullet from Petra's nose through her brain. It turns slightly several times, and comes to rest at the rear of her brain. And in the process, the bullet misses all the vital areas of the brain. In many ways, it almost misses the brain itself," he said.

Anderson has started physical and speech therapy and can walk, talk and laugh, said Andrew Roblyer, a family friend.

"I knew it was going to rack up in the hundreds of thousands, if not millions," West said of his friend's expected medical expenses.

Medley, who had been doing standup comedy routines in Denver and was working full-time at Target, had no health insurance, his brother Seth said.

Chloe Anderson has set up a similar fund for her sister, Petra Anderson, an aspiring musician who was also shot in the head. In a video posted Sunday asking for funds, Chloe Anderson notes that her mother was preparing to undergo cancer treatment later this month when Friday's shooting occurred. "My sister's hospital bills on top of that are making the financial reality look pretty daunting," she says. "So that's why we are reaching out to you -- the people who have already asked us what they can do to help."

By Wednesday evening, the fund had received more than $184,000 with a goal of $250,000.

Money is also streaming in to GivingFirst.org, which is accepting donations for the shooting victims and their relatives. By Tuesday, the amount had reached almost $2 million, Gov. John Hickenlooper said.

"The needs will be great and we look forward to seeing the fund grow exponentially," he said. "This money will help those impacted by this tragedy begin to recover and rebuild their lives."

Hickenlooper said donors include Warner Bros. and Legendary Pictures, co-producers of "The Dark Knight Rises."

Sources at Warner Bros. studios told CNN the company made a "substantial" donation. Warner Bros., a subsidiary of CNN's parent company Time Warner, would not divulge how much money it was giving out of respect for the victims, the sources said.

Shooting suspect Holmes booby-trapped his Aurora apartment with more than 30 homemade grenades and 10 gallons of gasoline, a law enforcement official who viewed video showing the apartment's interior has told CNN.

The sophisticated setup inside the sparsely furnished third-floor, one-bedroom apartment was meant to harm, or possibly kill, anyone who entered -- and tested the skills of bomb squad members charged with clearing it, the official said.

Tenants of the three-story, brick apartment building were allowed to return Wednesday night to sleep in their apartments for the first time since early Friday, when police went door-to-door and rousted them.

The Holmes family issued a statement Friday saying, "Our hearts go out to those who were involved in this tragedy and to the families and friends of those involved." It added, "We are still trying to process this information."